G. Cardenas et al., THERMAL STUDIES OF METAL-FILMS PREPARED WITH OXYGENATED SOLVENTS .12., Boletin de la Sociedad Chilena de Quimica, 39(3), 1994, pp. 199-204
Copper, silver and gold colloids have been prepared by Chemical Liquid
Deposition (CLD) with dimethoxymethane, 2-methoxyethyl ether and ethy
lenglycol dimethyl ether. The metals are evaporated to yield atoms whi
ch are solvated at low temperatures and during the warm up process col
loidal sols with metal clusters are obtained. Evaporation of the solve
nt was carried out under vacuum generating metal films. These films ar
e showing very low carbon/hydrogen content and were characterized by e
lemental analyses and infrared spectroscopy. The thermal stabilities o
f these metal films have been studied by thermogravimetry (TG) between
25 and 550-degrees-C under nitrogen flow. The decomposition temperatu
re was obtained from the maximum of the first derivative from TG curve
. The kinetic parameters of the thermal decomposition were determined
by the Arrhenius equation. All these films degrade in a single step. T
he kinetic data thus obtained show that the thermostabilities decrease
in the order: Au-DMM > Au-EDE > Cu-DMM > Cu-EDE > Ag-EDE > Ag-DMM > A
u-2-MEE > Ag-2-MEE > Cu-2-MEE. The thermal stability seems to depend o
n the metal and on the size of the ligand. The decomposition reaction
order is zero for Au, Ag-DMM and Au-EDE. However, n = -0.25 was obtain
ed for the other films. This means that we are in the presence of a mu
ltistep decomposition mechanism. The pre-exponential factor, the react
ion order, the decomposition temperature and the activation energy of
the decomposition reaction for Ag, Au and Cu films have been determine
d.